I've had my JMs now for 3-4 years (8 diff trees, of diff cultivars)... and not one has died. They are all healthy with a 3-5gal pot full of roots.
But... what does die every year is azaleas, whether satsuki or kurume (not interested in sun-tolerant indicas... as they get too big like camelias).
First year, 6-7 starter-plants I bought died.
2nd and 3rd year, about 50 rooted cuttings either dried up from the summer, or others got eaten by rats.
This year, 8-9 well-rooted 1yo cuttings (and counting) dried up once summer hit.
Currently, only got 10 kurume and 5-6 satsuki left that seem healthy and still growing... hope they make it through summer.
Azaleas seem much more difficult than JMs for me.